The FBI had been seeking Bulger since he fled Boston in 1994 as he was being sought in connection with at least 19 murders and other charges. He and longtime companion Catherine Greig, 60, were taken into custody after authorities received a tip, the FBI said.

Bulger and Greig are scheduled to appear in federal court in downtown Los Angeles on Thursday.

Authorities seized weapons and a large amount of cash inside their apartment, sources told the Los Angeles Times.

It's unclear how long they lived on 3rd Street in Santa Monica, but if they were hiding, they were doing so in plain sight of neighbors.

"The seemed normal," said an attorney who lived in the Princess Eugenia complex, where Bulger and Greig had an apartment on the third floor.

"It's a little surprising," the neighbor said of the arrest. "It's a little disconcerting."

"I'm sure I've seen him around!" added resident Sonia Veronika.

Bulger was believed to have been traveling with Greig for the last several years, according to the FBI. Greig, petite and blond with blue eyes, was a dental hygienist by occupation. Authorities said she dyed her hair darker to disguise her appearance. A media campaign launched in an attempt to develop leads on Bulger was aimed at women in their 60s, the same demographic as Greig.

Authorities said Bulger initially fled after being tipped by John Connolly Jr., a then-FBI agent who was using Bulger as an informant. Connolly was convicted of racketeering in May 2002 for protecting Bulger and another reputed crime boss and FBI informant, Stephen "The Rifleman" Flemmi.

In 2000, an unconfirmed sighting of Bulger was reported in Orange County. A man told authorities he believed he saw Bulger outside a Fountain Valley hair salon where a woman who may have been Greig was having her hair done. The last credible sighting of him was in London in 2002, the FBI said. He was believed to have altered his appearance and have been traveling extensively through Europe, Mexico, Canada and the United States.

At least half a dozen agents were searching the trunk of a car in the garage in Bulger's apartment complex overnight.